The update for Android 4.4 rendered tablet useless, now what do I do?

I did update last night for android 4.4. Now I cannot access anything on my sdcard. I have lost data. My game apps graphics are missing parts and the other parts are showing in reverse. Many apps are not even accessible. My tablet has become useless now and I am furious about all the money I spent on it. Please fix this with newer update asap. These kind of android issues may drive people to apple! I need to be able to access my SD card by writing to it and reading from it.